Scientists are expressing shock and elation over a fossil-find that revisits life half a billion years ago—and may just shake up our view of evolution, the Guardian reports. Reported in Science, the Qingjiang site in China includes at least 4,351 fossils representing 101 species, 53 of them new to science. The primitive sponges, algae, jellyfish, and other creatures are also captured in incredible detail, with mouths, eyes, muscles, and gills all visible. The "preservational quality is mindblowing," says paleontologist Martin Smith, who describes the fossils as having "detail finer than a human hair." And they're from a vital period, the Cambrian explosion, when animal life erupted on Earth and rooted the tree of life.
Like all Cambrian life, these small creatures lived at sea, but were forever changed when a mudflow swept them into colder, deeper water, where they were buried without much oxygen to cause decomposition, per Phys.org. Study author Dongjing Fu and coauthor Xingliang Zhang found them in 2007 when digging through riverbank shale and spent four years unearthing the find, National Geographic reports. Now scientists say it could fill in our knowledge of key animal groups, per the Smithsonian, and better explain how they led to modern species. It's also being compared to two earlier Cambrian fossil sites, the 508-million-year-old Burgess Shale in Canada and 518-million-year-old Chengiang find in China. "I can see a bright future," says Fu. "Qingjiang will be the next Burgess shale." (Read more fossils stories.)